Windows only: The Sysinternals Suite contains a large collection of individually executable PC troubleshooting utilities by Mark Russinovich from Sysinternals (which was recently swallowed by Microsoft).

If the name Sysinternals sounds familiar, it's because we've suggesteda few Sysinternals apps in the past (and so haveyou). With handy tools from the popular Process Explorer to Autologon tool and RootkitRevealer (the very one that discovered Sony's rootkit last year), the Sysinternals Suite is a useful tool to have on hand. The suite of applications is free to download, Windows only. — Adam Pash